ESSENTIALS OF BOTANY 



3. Examination of the Bean. — Study the seed, both dry and after 

 twelve hours' soaking, in the same general way in which the squash 

 seed has just been examined.^ 



Notice the presence of a distinct plumule, consisting of a pair of 

 rudimentary leaves between the cotyledons, just where they are 



joined to the top of the hypocotyl. In 

 many seeds (as the pea) the plumule 

 does not show distinct leaves. But 

 in all cases the plumule contains the 

 growing point, the tip of the stem from 

 which all the upward growth of the 

 plant is to proceed. 



Make a sketch of these leaves as they, 

 lie in place on one of the cotyledons 

 after the bean has been split open. 



Note the cavity in each cotyledon 

 caused by the pressure of the plumule 

 and of the hypocotyl.^ 



4. Germination of the Grain of Corn. 

 — Soak some grains of corn and plant 

 them as directed in Sect. 1.^ 



Make six or more sketches at various 

 stages to illustrate the growth of the 

 plumule and the formation of roots ; 

 first a main root from the base of the 

 embryo, then others more slender from 

 the same region, and later on still 

 others from points higher up on the 

 stem. The student may be able to dis- 

 cover what becomes of the large outer 



Pig. 



2. Young Seedling of 

 Windsor Bean. 



, cotyledon ; r, root ; s, stem. 



1 The larger the variety of bean chosen, the easier it will he to see and 

 sketch the several parts. The large red kidney bean, the horticultural bean, 

 or the Lima bean "will do well for this examination. 



^ The teacher will find excellent sketches of most of the germinating 

 seeds described in the present chapter in Newell's Outlines of Lessons in 

 Botany, Part I. 



3 The pupil may economize space by planting the new seeds in boxes 

 from which part of the earlier planted seeds have been dug up for use in 

 sketching, etc. 



